Correct Answer: C

Rationale: The field is a hexagon with six equal sides, each 320 feet long. To find the total cost of fencing material needed, multiply the cost per foot ($75) by the total perimeter of the field (6 sides x 320 feet). Therefore, the total cost will be $75 x 6 x 320 = $3,360. Thus, the farmer will need to spend $3,360 on fencing material. Choice A, $2,240, is incorrect as it does not account for the total perimeter of the field. Choice B, $2,800, is incorrect as it underestimates the total cost by not considering all sides of the hexagon. Choice D, $4,480, is incorrect as it overestimates the total cost by multiplying incorrectly or considering extra sides.

Correct Answer: C

Rationale: To find the amount of blood used for further tests, we multiply 500 mL by 0.1666 (equivalent to 16.66%). This calculation results in 83.3, which rounded to the nearest hundredth is 83.33. Therefore, 83.33 milliliters of blood were used for further tests. Choice A is incorrect as it does not consider rounding to the nearest hundredth. Choices B and D are slightly off due to incorrect rounding. Choice C is the correct answer after rounding to the nearest hundredth.

Correct Answer: A

Rationale: To find the actual distance in miles, you need to set up a proportion using the scale provided (1 inch = 45 miles). Since the distance on the map is 3.2 inches, you can set up the proportion: 1 inch / 45 miles = 3.2 inches / x miles. Cross-multiply to solve for x: 1 * x = 45 * 3.2, x = 144. Therefore, the actual distance in miles is 144. Choices B, C, and D are incorrect because they do not accurately calculate the actual distance using the scale provided.

Correct Answer: C

Rationale: When reducing a figure by a scale factor, each dimension is multiplied by the same scale factor. In this case, the scale factor is not provided in the question. To find the scale factor, you would divide the new lengths of the sides by the original lengths. The scaled-down triangle's dimensions are the original dimensions multiplied by the scale factor. By performing the calculations, the dimensions of the dilated triangle are 6.75 cm, 3 cm, and 5.25 cm, which matches choice C. Choices A, B, and D have incorrect dimensions as they do not result from the correct application of the scale factor to the original triangle's dimensions.

Correct Answer: C

Rationale: Let's denote the number of cars containing only a man as M, only a woman as W, and both a man and a woman as B. Given that there are 25 cars in total, we have: M + W + B = 25 From the information provided, we know that 13 cars contain a woman (W) and 20 cars contain a man (M). Since each car contains either one man, one woman, or both, the cars that contain both a man and a woman (B) are counted once in each of the M and W categories. Therefore, to find out how many cars contain both a man and a woman, we need to subtract the number of cars that contain only a man and only a woman from the total cars. M + B = 20 (as 20 cars contain a man) W + B = 13 (as 13 cars contain a woman) Solving the above two equations simultaneously, we get: M = 12, W = 5, B = 8 Therefore, 8 cars contain both a man and a woman. Hence, the correct answer is 8. Choice A, B, and D are incorrect as they do not reflect the correct calculation based on the information provided.